The need for network architectures that provide broad frequency bandwidth is evident from the increased user demand for programs, products and services such as high speed Internet access, voice-over-Internet protocol (VoIP), video-on-demand (VOD), interactive television, digital HDTV, and broadband telephony services such as videophone, videoconferencing, etc. Improvements to meet this need must deliver hundreds of Megabits per second, in send and receive modes, and preferably in duplex, i.e., simultaneously sending and receiving.
Cable companies, telecommunications companies, satellite and wireless providers, and other service providers have developed a number of methods to increase frequency bandwidth. For example, newer communication lines being built today are based on fiber optic technologies which are capable of transmitting large volumes of information at very high speeds (high-bit-rate data transmission). Most cities are linked by communication lines capable of carrying information such as video and voice data, requiring a high frequency bandwidth.
Little or no feasible technology presently exists, however, to deliver high frequency bandwidth, and in particular two-way bandwidth, at the user terminal end of existing communication networks. One reason for this is that the commonly referred to “last mile” local drop to the end user is typically still the legacy copper line installed decades ago for telephone service. Because the legacy copper lines were designed for performance that did not contemplate today's fiber optic capabilities, the end users with copper lines cannot avail themselves of the high bit rates that a modern long haul infrastructure can provide. Quite simply, the legacy links as well as the architecture of the central office (telephone exchange) cannot deliver the information transfer capability desired for all the data, video, etc. The end user has thus been limited by his or her local drop (or “last-mile”) connection to the service provider.
Fiber optic cable lines and satellites may provide suitable transmission of high frequency communication signals, but these methods are not without drawbacks. For instance, laying cable lines to every end user is cost prohibitive, especially in an urban environment. Satellites, although capable of transmitting high frequency data, are limited due to both spectrum allocations and to a limited number of orbital slots; that is, there is insufficient capacity to deliver high bandwidth service to millions of users. Moreover, the complexities involved with high frequency two-way satellite bandwidth (duplex mode) render it too difficult and expensive to implement.
Short-wavelength optical systems also have been proposed, claiming optical data transmission with high bandwidth. Short-wavelength optical systems at near and visible frequencies, however, suffer from the inability to penetrate inclement weather such as clouds and rain.
In view of the aforementioned shortcomings associated with present communication and information networks, there exists a strong need for a communication system and method that can transmit and receive information with respect to the last-mile using a high frequency broadband carrier.